This invention relates generally to trains, and more specifically to train operating efficiency.
Typically, in order to move freight via railway from one location to another, a long or very long train is utilized. Increasing a length of a train allows more freight to be carried without additional on-board personnel. Adding more cars, however, decreases average travel speed of the train, increases fuel consumption, and ties up sections of track for longer time periods. Increasing train length also increases braking distances and causes additional stress to couplers between cars.
It would be desirable to provide a method for increasing train freight capacity without reducing average train speed or causing additional wear to train components.
In an exemplary embodiment, a method for increasing operation efficiency of trains includes operating a plurality of trains as a moving sequence and regulating distances between the trains to eliminate distances in excess of safe minimum distances between the trains. Distance between a preceding train and a following train is regulated by varying speed of the following train to minimize an excess distance between the two trains.
A safe minimum distance between the preceding train and the following train includes a safe braking distance for the following train. In a further embodiment a safe braking distance is determined based on train weight distribution. Distributed weight of a moving train is estimated using, at various times, measurements of train position, speed, acceleration and tractive effort to estimate forces affecting the train. At various times the forces are related to one another to obtain a matrix equation expressing the forces in terms of car weight and train weight. The matrix equation then is solved to determine car weight and train weight.
The above method increases effective track capacity and equipment utilization while reducing fuel consumption. Use of shorter trains also facilitates train handling in railroad yards and thus reduces yard operating time.